Answer: It may be that the previous owners added topsoil over a plastic weed barrier. As long as you have pierced the plastic when digging the planting holes for your plants, the plastic shouldn't hinder root growth. If you simply planted on top of the plastic, the roots will eventually die off. Since you've only recently planted, if you know you did not dig through the plastic while installing your plants, take the time now to dig them up, puncture the plastic, then replant. The roots should be fine as long as you leave a large area around each plant to apply water. Best wishes with your new flower bed!
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